Velocity measuring device

ABSTRACT

Disclosed herein is a velocity measuring device to be used in a moving frame to determine the velocity of the moving frame. At least one beam of light is emitted from a site in the moving frame and travels to a mirror disposed in the moving frame and back to the site at which the emission occurred, after which the beam is detected by a detector. By measuring the round trip time of the light beam from emission to detection, a factor gamma can be determined from which the velocity of the moving frame can be computed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Applications Ser. 62/951,656,titled VELOCITY MEASURING DEVICE, filed on Dec. 20, 2019, and herebyincorporates by reference in its entirety U.S. Application Ser.62/951,656 into the present application.

BACKGROUND

Special relativity relies on two premises, (1) that the laws of physicsare the same in all inertial frames, and (2) that the speed of light isconstant in all frames of reference. These premises lead to conceptssuch as the relativity of simultaneity, which states that events thatare simultaneous in one inertial frame are not simultaneous in anotherinertial frame stemming from the idea that a moving object carries itsown time. However, these consequences lead to paradoxes. A newinterpretation of the above premises is needed if physics is to regain afooting in physical reality.

SUMMARY

The new interpretation returns to the concept of universal simultaneity.The interpretation introduces the theory of energy-time. The energy-timetheory rests in part on the notion that a simultaneity detector can beused to determine the velocity of an inertial frame.

One embodiment provides a method for determining a velocity of aninertial frame in the inertial frame moving with respect to a referenceframe. The method includes triggering emission of a light beam from asite on a substrate in the inertial frame, where the site is at aposition halfway between ends of the substrate, a mirror is disposed onthe substrate at one end of the substrate, and the emitted light beamtraverses a path towards the mirror. The method further includesdetecting when the light beam returns to the site after being reflectedfrom the mirror, determining a first time interval which has elapsedbetween the triggering and the detecting and computing a ratio of thefirst time interval to a second time interval; and calculating thevelocity based on the ratio.

Further embodiments include an apparatus configured to carry out one ormore aspects of the above method. Further embodiments also include usingthree velocity-measuring devices, mutually orthogonal to each other, tomeasure velocity in three orthogonal directions, where each devicemeasures velocity in the direction of the physical path of the lightbeams in each device. Yet a further embodiment includes a single devicethat can be oriented in three mutually orthogonal directions to measurevelocity sequentially in the three directions.

One advantage of the embodiments described herein is that the deviceprovides a way of measuring velocity without the use of a globalpositioning system (GPS) or a gyroscope. Another advantage is that thedevice can be used as a backup system as well as for calibration of aprimary velocity measuring system for large ships such as carriers ortankers and large airplanes such as 747s and 380s. Yet another advantageis that a measurement can be repeated many times for a system whosevelocity continuously varies.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A depicts a device for determining the velocity of an inertialframe, in an embodiment.

FIG. 1B depicts a controller for the device, in an embodiment.

FIG. 2 depicts a time-space diagram for the case when the device is notmoving.

FIG. 3 depicts a time-space diagram for the case when the device ismoving with respect to a reference frame.

FIG. 4 depicts a flow of operations for carrying out a velocitydetermination, in an embodiment.

DETAILED DESCRIPTION

FIG. 1A depicts a measuring device for determining the velocity of aninertial frame, in an embodiment. In the figure, the device 100 includesa controller 120 with a light emitting device interface 122 and a lightdetecting device interface 124, a light-emitting device 104, and a lightdetecting device 106 mounted at the exact center of the substrate 102 ofthe measuring device 100, the substrate having length L. Also includedare a mirror mounted at one end of the substrate, mirror A 108, and amirror at the other end of the substrate, mirror B 110 supportedrespectively by support A 112 and support B 114. The light path betweenthe light-emitting device 104 and each mirror A 108, B 110 is identicalto the light path between each mirror A 108, B 110, and the lightdetecting device 106. Moreover, the light beams in each of the pathstraverse a light-slowing medium 116, 118, such as glass, so that thedevice 100 can have a compact size and detect velocities that are smallwith respect to the speed of light. Even though in the figure, lightbeams are depicted as traveling on a 45-degree physical path to aid indrawing the emitter and detector, this need not be the case; however,the physical paths of the light beams are preferably collinear. Forexample, the light beams can travel on a zero degree path between theemitter and mirror and between the mirror and detector if the emitterand detector are in the same position on the substrate. All that isrequired is that the path length of beam A and the path length of beam Bbe the same.

In some embodiments, a single beam and mirror are used. For example,only beam A and mirror A or only beam B and mirror B are employed on thesubstrate.

FIG. 1B depicts the controller for the device, in an embodiment. Thecontroller includes the light emitting device 122 and the lightdetecting device 124 coupled to a bus 130. Also coupled to the bus 130are one or more CPUs 126, a RAM 128, and a timer 132. The RAM 128 may bea volatile or non-volatile memory and contains one or more programs foroperating the device 100.

FIG. 2 depicts a time-space diagram for the case when the device 100 isnot moving. In the diagram, the speed of light, c is assumed to be equalto 1, time is on the vertical axis, and length, x, in one dimension isplotted on the horizontal axis. Thus, the time axis is an axis ofconstant position, and the x-axis is an axis of constant time or a lineof simultaneity. When shown on a time-distance diagram, the axes arescaled so that a beam of light having a speed of unity=(1 unit ofdistance/1 unit of time) travels on a velocity line at a ±45-degreeangle. However, depiction of light moving on a velocity line in thetime-distance diagram is not to be confused with the physical path thelight beams take in a physical device, which are preferably collinear.

According to the figure, the light beam is emitted by the light emitterat the center of the substrate and travels to each mirror at the ends.At the mirrors, the light beam reflects, and each beam moves backtowards the light detector. When the light detector flashes, itindicates that both beams have arrived at the light detector. The lengthof the substrate is set at one (1) unit, and the diagram computes thatthe time between the emission of the beams and their subsequentdetection is 1 unit. Algebraically, the time t_(A) for beam A to reachthe detector is L/c and the time t_(B) for beam B to reach the detectoris also L/c. Because L=1 and c=1, the total round-trip time intervalτ=t_(A)=t_(B)=1, as shown in the diagram. A frame in which the roundtrip time interval τ=L/c is hereinafter referred to as the referenceframe.

In some embodiments, a single beam, beam A, or beam B is used toimplement the device as the measured time for beam A t_(A) or beam Bt_(B) equals τ.

FIG. 3 depicts a time-space diagram for an example case when the deviceis moving with respect to a reference frame. In the diagram, the axesare scaled so that c is still equal to 1. Accordingly, a light beamtravels on a velocity line at a 45-degree angle, where the velocity linein the graph is not the physical path of the light beam but only agraphical representation of the velocity. Also in the example depicted,the ends and middle of the substrate move at a speed of ½ the speed oflight, i.e., 0.5 c=0.5. Device movement means that velocity lines forthe ends and middle of the substrate are lines at an angle ofarctan(velocity)=arctan(0.5)=0.4636 radians, which is 26.565 degreesrotated to the right from the vertical axis, which is a slope of 0.5,i.e., 1 unit of distance per 2 units of time. Because of universalsimultaneity, the line of simultaneity, i.e., the x-axis, is the same asin FIG. 2.

According to the diagram, the time between the emission (event A) of thelight beams from the light emitter and their detection (event B) at thedetector is 1.33 time units because the substrate is moving at 0.5c. Thetime for beam A to reach mirror A is 0.33 time units and the time forbeam A to reach the detector is 1.0 time unit, for a total t_(A) of 4/3time units. The time for beam B to reach mirror B is 1.0 time units, andthe time for beam B to reach the detector is 0.33 time units, for atotal t_(B) of 4/3 time units. Thus, the measured time for either beam Aor beam B is the same.

Algebraically, the measured total time for beam A to travel to mirror Aand return is

${\tau_{measured} = {{\gamma^{2}\frac{L}{c}} = {{\frac{4}{3}\frac{L}{c}} = {{\frac{4}{3}\mspace{14mu}{with}\mspace{14mu} c} = 1}}}},$L=1. The measured time, τ_(measured), is the time for an observer of themoving frame in the reference frame. In other words, the measured roundtrip time τ_(measured) is γ² times that of the reference frame, which isL/c. The symbol γ² is chosen in anticipation of the computation of thevelocity, which is possible because γ² also equals 1/(1−ν²/c²), asexplained below. Given this relationship, ν=c√{square root over(1−1/γ²)}. In the example given, γ²=4/3, so ν=c√{square root over(1−¾)}=0.50c.

However, it is established that a clock in the moving frame runs moreslowly than a clock in the reference frame by a factor of γ. Thus, thetime measured t_(m) in the moving frame is

$\tau_{m} = {{\tau_{measured}/\gamma} = {{\gamma\frac{L}{c}} = {\sqrt{4/3} = {{1.1}547}}}}$and thus γ can be derived from the measurement τ_(m) because L/c isknown. Also, because the relationship γ=1/(1ν²/c²) still holds. Thevelocity can be computed as ν=c√{square root over (1−1/1/γ²)}.

As mentioned above, the light beams may travel in a light-slowingmedium. When the light beams do so, then detection of velocities thatare small compared to c is improved. For example, if the light slowingmedium causes c′, the speed in the light slowing medium, to equal 0.01c,then γ² still equals 4/3 when the speed of the substrate is 0.005c.Thus, the greater the slowing of light by the light slowing medium, themore accurately that smaller velocities can be measured. Moreover, withthe light-slowing medium, a more compact device can be manufacturedbecause light does not have to travel large distances in the device.

FIG. 4 depicts a flow of operations for carrying out a velocitydetermination. In step 402, the controller 120 triggers the emitter toemit a beam, say beam A, and starts the timer 132. In step 404, beam Ais detected at the detector after having been reflected from theirrespective mirrors. The detection of the beam notifies the controller tostop the timer 132. In step 406, a first time interval between thetriggering and the detecting is then determined from the timer 132 bythe controller 120. The first (measured) time interval ist_(A)=τ_(measured). In step 408, the controller 120 computes a ratio,

${\left( \frac{\tau_{measured}}{\gamma} \right)\left( {L/c} \right)},$of the first time interval to a second time interval, where the secondtime interval is (L/c). This ratio equals γ, but γ is also related tothe components t_(A1), t_(A2) of total round trip time,t_(A)=τ_(measured), where

$\begin{matrix}{t_{A1} = {\frac{L}{2}\left( \frac{1}{c + v} \right)}} & (1)\end{matrix}$is the time interval for beam A to reach mirror A, and

$\begin{matrix}{t_{A2} = {\frac{L}{2}\left( \frac{1}{c - v} \right)}} & (2)\end{matrix}$is the time interval for beam A to reach the detector after reflectionfrom the mirror and

$\begin{matrix}{\tau_{measured} = {{t_{A\; 1} + t_{A2}} = {{\left( \frac{L}{c} \right)\left( \frac{1}{1 - \frac{v^{2}}{c^{2}}} \right)} = {\frac{L}{c}{\gamma^{2}.}}}}} & (3)\end{matrix}$(Similar equations apply to beam B so that either beam A or beam B canbe used for the measurement.)Therefore, from inspection of equation 3 above,

$\begin{matrix}{\gamma^{2} = {\left( \frac{1}{1 - \frac{v^{2}}{c^{2}}} \right).}} & (4)\end{matrix}$In step 410, the controller 120 computes the velocity of the movingsubstrate ν as c√{square root over (1−1/γ²)} which follows from equation4.

Thus, the velocity of a moving frame with respect to a reference frameis determined.

In another embodiment, a differential velocity can be determined bydetermining the velocity ν₁ (from a time measurement as described above)of a second frame with respect to a first reference frame and thendetermining the velocity ν₂ of a third frame moving with respect to thefirst reference frame. The difference ν₂−ν₁ is the velocity of the thirdframe with respect to the second frame. For example, the first referenceframe has γ²=1, so that the frame is not moving. The second frame hasγ²=9/8 based on a time measurement in the second frame, so that itsspeed is ⅓ c. The third frame has γ²=4/3 based on a time measurement inthe third frame, so that its speed relative to the first reference frameis 0.5c. The difference in speed is 0.5c−0.3c=0.2c, which is the speed(differential velocity) of the third frame relative to the second framefor collinear motion among the frames.

In conclusion, because time is the same in both the frame of the movingsubstrate and the reference frame, the velocity of the moving frame canbe measured by an experiment entirely within the moving frame.

The various embodiments described herein may employ variouscomputer-implemented operations involving data stored in computersystems. For example, these operations may require physical manipulationof physical quantities—usually, though not necessarily, these quantitiesmay take the form of electrical or magnetic signals, where they orrepresentations of them are capable of being stored, transferred,combined, compared, or otherwise manipulated. Further, suchmanipulations are often referred to in terms, such as producing,identifying, determining, or comparing. Any operations described hereinthat form part of one or more embodiments of the invention may be usefulmachine operations. In addition, one or more embodiments of theinvention also relate to a device or an apparatus for performing theseoperations. The apparatus may be specially constructed for specificrequired purposes, or it may be a general purpose computer selectivelyactivated or configured by a computer program stored in the computer. Inparticular, various general purpose machines may be used with computerprograms written in accordance with the teachings herein, or it may bemore convenient to construct a more specialized apparatus to perform therequired operations.

The various embodiments described herein may be practiced with othercomputer system configurations including hand-held devices,microprocessor systems, microprocessor-based or programmable consumerelectronics, minicomputers, mainframe computers, and the like.

One or more embodiments of the present invention may be implemented asone or more computer programs or as one or more computer program modulesembodied in one or more computer-readable media. The termcomputer-readable medium refers to any data storage device that canstore data which can thereafter be input to a computersystem—computer-readable media may be based on any existing orsubsequently developed technology for embodying computer programs in amanner that enables them to be read by a computer. Examples of acomputer-readable medium include a hard drive, network-attached storage(NAS), read-only memory, random-access memory (e.g., a flash memorydevice), a CD (Compact Discs)—CD-ROM, a CD-R, or a CD-RW, a DVD (DigitalVersatile Disc), a magnetic tape, and other optical and non-optical datastorage devices. The computer-readable medium can also be distributedover a network-coupled computer system so that the computer-readablecode is stored and executed in a distributed fashion.

Although one or more embodiments of the present invention have beendescribed in some detail for clarity of understanding, it will beapparent that certain changes and modifications may be made within thescope of the claims. Accordingly, the described embodiments are to beconsidered as illustrative and not restrictive, and the scope of theclaims is not to be limited to details given herein, but may be modifiedwithin the scope and equivalents of the claims. In the claims, elementsand/or steps do not imply any particular order of operation, unlessexplicitly stated in the claims.

Plural instances may be provided for components, operations orstructures described herein as a single instance. Finally, boundariesbetween various components, operations and data stores are somewhatarbitrary, and particular operations are illustrated in the context ofspecific illustrative configurations. Other allocations of functionalityare envisioned and may fall within the scope of the invention(s). Ingeneral, structures and functionality presented as separate componentsin exemplary configurations may be implemented as a combined structureor component. Similarly, structures and functionality presented as asingle component may be implemented as separate components. These andother variations, modifications, additions, and improvements may fallwithin the scope of the appended claims(s).

What is claimed is:
 1. An apparatus for determining a velocity of asubstrate moving with respect to a reference frame, the apparatuscomprising: the substrate; a light beam emitter disposed on thesubstrate at a site that is halfway between ends of the substrate; alight beam detector disposed on the substrate at the site of the lightbeam emitter; a mirror disposed on one end of the substrate; and acontroller coupled to the light beam emitter and light beam detector;wherein the controller is configured to trigger the light beam emitterto emit a light beam that travels to the mirror, and reflects from themirror and to receive a detection signal when the light beam is detectedby the light beam detector; and wherein the controller is furtherconfigured to calculate the velocity of the moving substrate withrespect to the reference frame based on the controller measuring in themoving substrate a first time interval between emitting the light beamfrom the light beam emitter and detecting the light beam at the lightbeam detector and comparing the first time interval to a second timeinterval.
 2. The apparatus of claim 1, further comprising: a firstmedium, wherein the light beam travels to and from the mirror in thefirst medium; and a second medium, wherein the other light beam travelsto and from the other mirror in the second medium which is identical tothe first medium.
 3. The apparatus of claim 2, wherein the first mediumand the second medium are light-slowing media.
 4. The apparatus of claim3, wherein the light-slowing media are glass media.
 5. The apparatus ofclaim 1, wherein the light beam emitter, when triggered by thecontroller, emits another light beam that travels to another mirrordisposed at the other end of the substrate, reflects from the othermirror and is detected by the light beam detector; wherein thecontroller is further configured to receive a detection signal when theother light beam is detected by the light beam detector; wherein thecontroller is further configured to measure a third time intervalbetween emitting the other light beam and detecting the other light beamat the light beam detector; and wherein the third time interval equalsthe first time interval.
 6. The apparatus of claim 1, wherein the secondtime interval is a time between emitting and detecting when the velocityof the substrate is zero.
 7. The apparatus of claim 1, wherein a ratioof the first time interval to the second time interval is γ², whereγ²=1/(1−ν²/c²), c is the speed of light and ν is the velocity of themoving substrate.
 8. The apparatus of claim 1, wherein calculation ofthe velocity includes computing a quantity c√{square root over(1−1/γ²)}, where γ2=1/(1−ν²/c²) c is the speed of light and ν is thevelocity of the moving substrate.
 9. A non-transitory computer-readablemedium comprising instructions executable in a computer system, whereinthe instructions when executed in the computer system cause the computersystem to carry out a method for determining a velocity of an inertialframe moving with respect to a reference frame, the method comprising:triggering emission of a light beam from a site on a substrate in theinertial frame, wherein the site is at a position halfway between endsof the substrate, and wherein a mirror is disposed on the substrate atone end of the substrate and the light beam traverses a path towards themirror; detecting when the light beam returns to the site after beingreflected from the mirror; determining a first time interval which haselapsed between the triggering and the detecting; computing a ratio ofthe first time interval to a second time interval; and calculating thevelocity based on the ratio.
 10. The non-transitory computer-readablemedium of claim 9, wherein the method further comprises: triggeringemission of another light beam from the site simultaneously withtriggering emission of the light beam from the site, wherein anothermirror is disposed on the substrate at the other end of the substrateand the other light beam traverses a path towards the other mirror;detecting when the other light beam returns to the site after beingreflected from the other mirror; and determining a third time intervalwhich has elapsed between the triggering of the other light beam and thedetecting of the other light beam, wherein the third time intervalequals the first time interval.
 11. The non-transitory computer-readablemedium of claim 9, wherein the ratio of the first time interval to thesecond time interval is γ², where γ²=1/(1−ν²/c²) c is the speed of lightand ν is the velocity of the moving inertial frame.
 12. Thenon-transitory computer-readable medium of claim 9, wherein calculationof the velocity includes computing a quantity c√{square root over(1−1/γ²)}, where γ²=1/(1−ν²/c²) is the speed of light and ν is thevelocity of the moving inertial frame.